Implantable medical devices have been applied more and more widely in modern medicine. Because of its unique applications, an implantable medical device generally requires the power supply that supplies power to it to be small volume, low power and high power transfer efficiency. Not only so, the implantable medical device but also generally has multiple working modes, such as a sleep mode, a measurement mode, a data transmission mode, and so on. In each different working mode, the same implantable medical device typically has a different requirement on the power supply that supplies power to it.
DC-DC converter is an important component of a power supply system of an implantable medical device. Conventional DC-DC converters usually cannot effectively satisfy different requirements of the implantable medical device in different working modes on the output voltage and the load values, which are in a relatively wide range. In addition, to improve the configurability, conventional DC-DC converters usually have relatively complicated circuits, relatively large chip areas, relatively high power consumption, and relatively low system working efficiency, and therefore are not suitable for supplying power to implantable medical devices.